In one example configuration, a heat recovery device for an exhaust line includes a valve body having at least one exhaust gas inlet and at least one exhaust gas outlet, the valve body inwardly defining a direct flow path for the exhaust gases from the inlet to the outlet. The device also includes a heat exchanger to exchange heat between exhaust gases and a heat transfer fluid. The heat exchanger includes a flow path for the exhaust gases and a flow path for the heat transfer fluid, the with flow path for the exhaust gases having upstream and downstream ends respectively emerging in inlet and outlet zones of the valve body, which are respectively situated relatively closer to the inlet and relatively closer to the outlet along the direct flow path. A shutter is arranged in the valve body and is movable relative to the valve body at least between a heat exchange position, in which the shutter closes off a cutoff section of the direct flow path and forces the exhaust gases to flow from the inlet toward the outlet through the heat exchanger along the exhaust gas flow path, and a short-circuit position, in which the shutter frees said cutoff section of the direct flow path and closes off the outlet zone. The shutter thus forces the exhaust gases to flow from the inlet toward the outlet along the direct flow path, the cutoff section being situated between the inlet zone and the outlet zone along the direct flow path.
When the shutter is in the short-circuit position, the exchanger is inactive. The exhaust gases flow from the inlet to the outlet of the valve body along the direct flow path.
However, residual heat transfers are observed from the exhaust gas to the heat transfer fluid. These residual heat transfers are also called parasitic losses.
In this context, the invention aims to propose a heat recovery device in which parasitic losses are reduced.